The Effects of Cardiorespiratory Fitness and Body Mass Index on the Development of Osteoarthritis in Women

Hathwar, Supriya, The Effect of Cardiorespiratory Fitness and Body Mass Index on the Development of Osteoarthritis in Women, (ACLS 1970-1999). Master of Public Health (Epidemiology), May, 35 pp., 6 tables, references, 48 titles. Osteoarthritis (OA) of the hip and knee is one of the most important causes of pain and disability affecting nearly 21 million people in the United States. Obesity is one of the primary causes of secondary osteoarthritis especially of the hip and knee. (Felson, 1992). The aim of this prospective cohort study is to determine whether higher levels of CRF reduce the risk of development of OA in women across different body mass index (BMI) levels. The study population consisted of 3847 women, ages 20-87, examined at the Cooper Clinic, Dallas, Texas between 1970 and 1999. There were 379 cases of physician-diagnosed OA during 31,657 woman-years of follow-up. After adjustment for age, exam year and health status, obesity and overweight were found to be significant predictors of OA in women. At all levels of CRF, the odds of developing OA increase as weight increases. In the overweight category, the odds of developing OA are 80% higher among the low-fit women [OR=1.8,95% CI (1.1-3.1)], and 60% higher among the moderately fit women [OR=1.6,95%CI (1.0-2.3)] compared to high fit, normal weight women. In the obese category, the low-fit and the high fit women had the same odds of developing OA (OR=2.6), while moderately fit women had lower odds of developing OA (OR=1.7). These data suggest that CRF is not a consistent predictor for development of OA in women.